From: "Ibrahim PAMUK (Ank,IH)" To: infrared posting Subject: Infrared filter Date sent: Tue, 28 Mar 2000 18:14:02 +0300 Send reply to: infrared@a1.nl Hi, The M&K 1000 or the Hoya RM100 is been compared and it seems that they are equal (http://www.irfilters.com/m&k_1000_filter.htm) . In WJ's homepage RG1000 was written to be similiar to RM900 or 094 of B+W that is #87A. So what is RM1000 and is B+W 094 still manufactured? Regards, Ibrahim From: "Willem-Jan Markerink" To: infrared@a1.nl Date sent: Sun, 2 Apr 2000 18:32:36 +0100 Subject: Re: Infrared filter Send reply to: infrared@a1.nl On 28 Mar 00 at 18:14, Ibrahim PAMUK (Ank,IH) wrote: > Hi, > > The M&K 1000 or the Hoya RM100 is been compared and it seems that they are > equal (http://www.irfilters.com/m&k_1000_filter.htm) . In WJ's homepage RG1000 > was written to be similiar to RM900 or 094 of B+W that is #87A. So what is > RM1000 and is B+W 094 still manufactured? My guess is that RM1000 has the transmission which RM90 *should* have had, based on it's equivalent-rating with #87A....#87A is definately opaque, but RM90 is not....to the eye it resembles a #89B or #88 (#88A is where it starts being opaque to the human eye). -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] From: "Willem-Jan Markerink" To: infrared@a1.nl Date sent: Mon, 3 Apr 2000 20:48:06 +0100 Subject: Re: Infrared filter Send reply to: infrared@a1.nl On 3 Apr 00 at 0:32, Marco Pauck wrote: > Willem-Jan Markerink wrote: > > > > On 28 Mar 00 at 18:14, Ibrahim PAMUK (Ank,IH) wrote: > > > > > The M&K 1000 or the Hoya RM100 is been compared and it seems that they are > > > equal (http://www.irfilters.com/m&k_1000_filter.htm) . In WJ's homepage > > > RG1000 was written to be similiar to RM900 or 094 of B+W that is #87A. So > > > what is RM1000 and is B+W 094 still manufactured? > > > > My guess is that RM1000 has the transmission which RM90 *should* have > > had, based on it's equivalent-rating with #87A....#87A is definately > > opaque, but RM90 is not....to the eye it resembles a #89B or #88 > > (#88A is where it starts being opaque to the human eye). > > I don't agree. Although I can see the filament of a light > bulb through my RM90, it is far stronger than the #88A! Mine definately isn't....I can look through the RM90 in sunlight, while I can't with #88A (#88 is the visible limit (shaded eye, very nice impression of the Wood-effekt btw), and RM90 doesn't even match that one). > To some details: I expose HIE as EI 25/15 with #88A but > EI 10/11 with RM90. Cor Breukel promised me a run on the spectrophotometer he has in his lab....once I have shipped all my exotic filters over to him, we'll let that machine speak it's neutral verdict....:-)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] From: "Charles Andrew" To: Subject: Re: Infrared filter Date sent: Mon, 3 Apr 2000 16:15:40 -0400 Send reply to: infrared@a1.nl I contacted the medical microscopy department at Johns Hopkins University in that they have many programs related to eye diseases and would be able to give an informed opinion and maybe give it some more thought. There are marked changes in glaucoma and in other diseases...maybe this is an interesting area in that glaucoma is a silent killer of sight and it goes undiagnosed and untreated, so maybe the answer isn't quite IR but maybe anothe wavelength might be of some help.